Woodturning lathes are commonly used for shaping wooden objects or workpieces according to patterns symmetrically disposed about the longitudinal center axis of the workpiece. The basic woodturning lathe includes spaced head and tail pieces designed to be adjusted toward one another and against the workpiece, the head and tail pieces being rotated then about an axis extended through the workpiece. A tool support provided adjacent the workpiece serves to steady a tool element which can be moved radially toward the rotating workpiece and axially along the length of the workpiece. Rotation of the workpiece accompanied by proper tool location thereby removes material for shaping the workpiece according to the required pattern.
The workpiece is commonly fixtured between the head and tail pieces by securement to a faceplate, which is in turn keyed to a rotating drive shaft or spindle. In many applications, the faceplate is flat and several screws fit through openings in the faceplate and are tapped directly into the end face of the workpiece. This means that after the workpiece has been shaped and removed from the lathe, the screwholes must be filled and the end face sanded. This is time consuming on the one hand and frustrating on the other, having scars on the workpiece even though extreme care and skill might have otherwise been exhibited in shaping the workpiece. Alternatively, a blank having a shape complementary to the intended workpiece might be formed of a durable service wood for holding the workpiece; however this requires very elaborate cutting and forming of the blank itself.
While metal lathes have more universally used chucks with movable jaws for holding a workpiece relative to the cutting member, chucks have not been universally used in wood lathes. One reason might be because of its added cost with its moving parts. Another reason might be because of its prohibited weight to be supported on the powered spindle. In this regard, the lathe typically has the drive shaft or spindle journalled from the powerhead in a cantilevered fashion toward the tail piece. The bearings for supporting such a spindle have in the past been marginal, particularly on a lower cost wood lathe of a domestic use quality, and have proved inadequate for supporting a conventional chuck on the spindle.
Several patents illustrating conventional chuck constructions include the Mowat U.S. Pat. No. 785,564 and the Reynolds U.S. Pat. No. 960,705 which provide a main faceplate structure and movable jaws adjustably mounted relative to the faceplate on adjustment screws. The Clark U.S. Pat. No. 1,025,784 further allows rotational adjustment of each chuck jaw about an axis parallel to the spindle itself. The Sloan U.S. Pat. No. 1,424,597 illustrates a support screw mounting for the chuck jaws adjustment screw. The Smart U.S. Pat. No. 1,535,183 and the Morris U.S. Pat. No. 2,177,326 each illustrates support bearings or retaining rings for holding the adjustment screws in place relative to the face plate.
Despite these many varied chuck constructions, none is suitable for use on woodworking lathes of average domestic use quality. Accordingly, all of the convenience and otherwise beneficial aspects for removably chuck-holding the workpiece relative to the powered rotating spindle are not available.